support multiple type of logs function

zhangdt · zhangdt · commit 5600da3231ff · 2018-06-01T19:21:11.000+08:00
1) log2(param)
2) log10(param)
3) log(param) base=e
4) log(base_number, param)
diff --git a/src/main/java/org/nlpcn/es4sql/SQLFunctions.java b/src/main/java/org/nlpcn/es4sql/SQLFunctions.java
@@ -1,5 +1,6 @@
 package org.nlpcn.es4sql;
 
+import com.alibaba.druid.sql.SQLUtils;
 import com.alibaba.druid.sql.ast.SQLExpr;
 import com.alibaba.druid.sql.ast.expr.*;
 import com.google.common.base.Joiner;
@@ -19,7 +20,7 @@ public class SQLFunctions {
 
     //Groovy Built In Functions
     public final static Set<String> buildInFunctions = Sets.newHashSet(
-            "exp", "log", "log10", "sqrt", "cbrt", "ceil", "floor", "rint", "pow", "round",
+            "exp", "log", "log2", "log10", "log10", "sqrt", "cbrt", "ceil", "floor", "rint", "pow", "round",
             "random", "abs", //nummber operator
             "split", "concat_ws", "substring", "trim",//string operator
             "add", "multiply", "divide", "subtract", "modulus",//binary operator
@@ -63,8 +64,6 @@ public static Tuple<String, String> function(String methodName, List<KVValue> pa
 
             case "floor":
             case "round":
-            case "log":
-            case "log10":
             case "ceil":
             case "cbrt":
             case "rint":
@@ -107,6 +106,24 @@ public static Tuple<String, String> function(String methodName, List<KVValue> pa
                 functionStr = field(Util.expr2Object((SQLExpr) paramers.get(0).value).toString());
                 break;
 
+            case "log2":
+                functionStr = log(SQLUtils.toSQLExpr("2"), (SQLExpr) paramers.get(0).value, name);
+                break;
+            case "log10":
+                functionStr = log(SQLUtils.toSQLExpr("10"), (SQLExpr) paramers.get(0).value, name);
+                break;
+            case "log":
+                List<SQLExpr> logs = Lists.newArrayList();
+                for (int i = 0; i < paramers.size(); i++) {
+                    logs.add((SQLExpr) paramers.get(0).value);
+                }
+                if (logs.size() > 1) {
+                    functionStr = log(logs.get(0), logs.get(1), name);
+                } else {
+                    functionStr = log(SQLUtils.toSQLExpr("Math.E"), logs.get(0), name);
+                }
+                break;
+
             default:
 
         }
@@ -252,6 +269,20 @@ public static Tuple<String, String> log10(String strColumn, String valueName) {
         return mathSingleValueTemplate("log10", strColumn, valueName);
 
     }
+    public static Tuple<String, String> log(SQLExpr base, SQLExpr strColumn, String valueName) {
+        String name = "log_" + random();
+        String result;
+        if (valueName == null) {
+            if (isProperty(strColumn)) {
+                result = "def " + name + " = Math.log(doc['" + Util.expr2Object(strColumn).toString() + "'].value)/Math.log("+Util.expr2Object(base).toString()+")";
+            } else {
+                result = "def " + name + " = Math.log(" + Util.expr2Object(strColumn).toString() + ")/Math.log("+Util.expr2Object(base).toString()+")";
+            }
+        } else {
+            result = Util.expr2Object(strColumn).toString()+";def "+name+" = Math.log("+valueName+")/Math.log("+Util.expr2Object(base).toString()+")";
+        }
+        return new Tuple(name, result);
+    }
 
     public static Tuple<String, String> sqrt(String strColumn, String valueName) {
 
diff --git a/src/test/java/org/nlpcn/es4sql/SQLFunctionsTest.java b/src/test/java/org/nlpcn/es4sql/SQLFunctionsTest.java
@@ -245,6 +245,20 @@ public void concat_ws_fields() throws Exception {
         Assert.assertTrue(contents.get(0).contains("-"));
     }
 
+    @Test
+    public void functionLogs() throws Exception {
+        MainTestSuite.setUp();
+        String query = "SELECT log10(100) as a, log(1) as b, log(2, 4) as c, log2(8) as d from "
+                + TestsConstants.TEST_INDEX + "/account limit 1";
+        CSVResult csvResult = getCsvResult(false, query);
+        List<String> content = csvResult.getLines();
+        System.out.println(content.toString());
+        Assert.assertTrue(content.toString().contains("2.0"));
+        Assert.assertTrue(content.toString().contains("1.0"));
+        Assert.assertTrue(content.toString().contains("0.0"));
+        Assert.assertTrue(content.toString().contains("3.0"));
+    }
+
     // todo: change when split is back on language
 //    @Test
 //    public void split_field() throws Exception {
